Packaged terminal air conditioner unit

ABSTRACT

A packaged terminal air conditioner unit includes a phase separator positioned within a casing of the packaged terminal air conditioner unit. The phase separator is coupled to a supply conduit that extends between an exterior coil and an interior coil of the packaged terminal air conditioner unit. The phase separator is configured for separating liquid refrigerant within the supply conduit from vapor refrigerant within the supply conduit.

FIELD OF THE INVENTION

The present subject matter relates generally to packaged terminal air conditioner units.

BACKGROUND OF THE INVENTION

Certain heat pump systems include a sealed system for chilling and/or heating air with refrigerant. The sealed systems generally include a throttling device for restricting a flow of refrigerant between an outdoor heat exchanger or coil and an indoor heat exchanger or coil of the sealed system. Various throttling devices are available, including capillary tubes, J-T valves, electronic expansion valves, etc. Within the throttling device, at least a portion of the refrigerant within the flow of refrigerant may vaporize.

Packaged terminal air conditioner units generally include a casing and a sealed system. Due to space constraints within the casing, selection of sealed system components for packaged terminal air conditioner units can be limited. For example, relatively small heat exchangers are generally used in packaged terminal air conditioner units due to space constraints within the casing. Utilizing small heat exchangers can result in a large pressure drop across the low pressure side heat exchanger and thereby negatively affect an efficiency of the packaged terminal air conditioner unit. To reduce such pressure drops, certain small heat exchangers include large diameter tubes and/or split refrigerant flow into multiple parallel tubes. However, such small heat exchangers reduce refrigerant velocity through the small heat exchangers and the refrigerant side heat transfer coefficient.

Accordingly, a packaged terminal air conditioner unit with features for reducing a pressure drop of refrigerant across a heat exchanger of the packaged terminal air conditioner unit would be useful. In particular, a packaged terminal air conditioner unit with features for reducing a pressure drop of refrigerant across a heat exchanger of the packaged terminal air conditioner unit without significantly reducing the refrigerant side heat transfer coefficient would be useful.

BRIEF DESCRIPTION OF THE INVENTION

The present subject matter provides a packaged terminal air conditioner unit. The packaged terminal air conditioner unit includes a phase separator positioned within a casing of the packaged terminal air conditioner unit. The phase separator is coupled to a supply conduit that extends between an exterior coil and an interior coil of the packaged terminal air conditioner unit. The phase separator is configured for separating liquid refrigerant within the supply conduit from vapor refrigerant within the supply conduit. Additional aspects and advantages of the invention will be set forth in part in the following description, or may be apparent from the description, or may be learned through practice of the invention.

In a first exemplary embodiment, a packaged terminal air conditioner unit is provided. The packaged terminal air conditioner unit includes a casing. A compressor is positioned within the casing. The compressor is operable to increase a pressure of a refrigerant. An interior coil is also positioned within the casing. An exterior coil is positioned within the casing opposite the interior coil. A reversing valve is positioned within the casing. The reversing valve is in fluid communication with the compressor in order to receive compressed refrigerant from the compressor. The reversing valve is configured for selectively directing the compressed refrigerant from the compressor to either the interior coil or the exterior coil. A supply conduit is also positioned within the casing. The supply conduit fluidly connects the interior coil and the exterior coil in order to direct refrigerant between the interior coil and the exterior coil. A phase separator is positioned within the casing. The phase separator is coupled to the supply conduit adjacent the interior coil. The phase separator is configured for separating liquid refrigerant within the supply conduit from vapor refrigerant within the supply conduit. The supply conduit directs the liquid refrigerant from the phase separator to the interior coil.

In a second exemplary embodiment, a packaged terminal air conditioner unit is provided. The packaged terminal air conditioner unit includes a casing that extends between an exterior side portion and an interior side portion. A compressor is positioned within the casing. The compressor operable to compress a refrigerant. An interior coil is positioned within the casing at the interior side portion of the casing. An exterior coil is positioned within the casing at the exterior side portion of the casing. A reversing valve is in fluid communication with the compressor in order to receive compressed refrigerant from the compressor. The reversing valve is configured for selectively directing the compressed refrigerant from the compressor to either the interior coil or the exterior coil. A supply conduit extends between the interior coil and the exterior coil. A phase separator is coupled to the supply conduit. The phase separator is configured for separating liquid refrigerant within the supply conduit from vapor refrigerant within the supply conduit. The supply conduit is configured for directing the liquid refrigerant from the phase separator to the interior coil.

In a third exemplary embodiment, a packaged terminal air conditioner unit is provided. The packaged terminal air conditioner unit includes a casing. A compressor is positioned within the casing. The compressor is operable to increase a pressure of a refrigerant. An interior coil is also positioned within the casing. An exterior coil is positioned within the casing opposite the interior coil. A reversing valve is positioned within the casing. The reversing valve is in fluid communication with the compressor in order to receive compressed refrigerant from the compressor. The reversing valve is configured for selectively directing the compressed refrigerant from the compressor to either the interior coil or the exterior coil. A supply conduit is also positioned within the casing. The supply conduit fluidly connects the interior coil and the exterior coil in order to direct refrigerant between the interior coil and the exterior coil. A phase separator is positioned within the casing. The phase separator is coupled to the supply conduit adjacent the exterior coil. The phase separator is configured for separating liquid refrigerant within the supply conduit from vapor refrigerant within the supply conduit. The supply conduit directs the liquid refrigerant from the phase separator to the exterior coil.

These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures.

FIG. 1 provides an exploded perspective view of a packaged terminal air conditioner unit according to an exemplary embodiment of the present subject matter.

FIG. 2 provides a schematic view of certain components of the exemplary packaged terminal air conditioner unit of FIG. 1.

FIG. 3 provides a schematic view of certain components of the packaged terminal air conditioner unit of FIG. 1 according to another exemplary embodiment of the present subject matter.

DETAILED DESCRIPTION

Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.

FIG. 1 provides an exploded perspective view of a packaged terminal air conditioner unit 100 according to an exemplary embodiment of the present subject matter. Packaged terminal air conditioner unit 100 is operable to generate chilled and/or heated air in order to regulate the temperature of an associated room or building. As will be understood by those skilled in the art, packaged terminal air conditioner unit 100 may be utilized in installations where split heat pump systems are inconvenient or impractical. As discussed in greater detail below, a sealed system 120 of packaged terminal air conditioner unit 100 is disposed within a casing 110. Thus, packaged terminal air conditioner unit 100 may be a self-contained or autonomous system for heating and/or cooling air.

As may be seen in FIG. 1, casing 110 extends between an interior side portion 112 and an exterior side portion 114. Interior side portion 112 of casing 110 and exterior side portion 114 of casing 110 are spaced apart from each other. Thus, interior side portion 112 of casing 110 may be positioned at or contiguous with an interior atmosphere, and exterior side portion 114 of casing 110 may be positioned at or contiguous with an exterior atmosphere. Sealed system 120 includes components for transferring heat between the exterior atmosphere and the interior atmosphere, as discussed in greater detail below.

Casing 110 defines a mechanical compartment 116. Sealed system 120 is disposed or positioned within mechanical compartment 116 of casing 110. A front panel 118 and a rear grill or screen 119 are mounted to casing 110 and hinder or limit access to mechanical compartment 116 of casing 110. Front panel 118 is mounted to casing 110 at interior side portion 112 of casing 110, and rear screen 119 is mounted to casing 110 at exterior side portion 114 of casing 110. Front panel 118 and rear screen 119 each define a plurality of holes that permit air to flow through front panel 118 and rear screen 119, with the holes sized for preventing foreign objects from passing through front panel 118 and rear screen 119 into mechanical compartment 116 of casing 110.

Packaged terminal air conditioner unit 100 also includes a drain pan or bottom tray 138 and an inner wall 140 positioned within mechanical compartment 116 of casing 110. Sealed system 120 is positioned on bottom tray 138. Thus, liquid runoff from sealed system 120 may flow into and collect within bottom tray 138. Inner wall 140 may be mounted to bottom tray 138 and extend upwardly from bottom tray 138 to a top wall of casing 110. Inner wall 140 limits or prevents air flow between interior side portion 112 of casing 110 and exterior side portion 114 of casing 110 within mechanical compartment 116 of casing 110. Thus, inner wall 140 may divide mechanical compartment 116 of casing 110.

Packaged terminal air conditioner unit 100 further includes a controller 146 with user inputs, such as buttons, switches and/or dials. Controller 146 regulates operation of packaged terminal air conditioner unit 100. Thus, controller 146 is in operative communication with various components of packaged terminal air conditioner unit 100, such as components of sealed system 120 and/or a temperature sensor, such as a thermistor or thermocouple, for measuring the temperature of the interior atmosphere. In particular, controller 146 may selectively activate sealed system 120 in order to chill or heat air within sealed system 120, e.g., in response to temperature measurements from the temperature sensor.

Controller 146 includes memory and one or more processing devices such as microprocessors, CPUs or the like, such as general or special purpose microprocessors operable to execute programming instructions or micro-control code associated with operation of packaged terminal air conditioner unit 100. The memory can represent random access memory such as DRAM, or read only memory such as ROM or FLASH. The processor executes programming instructions stored in the memory. The memory can be a separate component from the processor or can be included onboard within the processor. Alternatively, controller 146 may be constructed without using a microprocessor, e.g., using a combination of discrete analog and/or digital logic circuitry (such as switches, amplifiers, integrators, comparators, flip-flops, AND gates, and the like) to perform control functionality instead of relying upon software.

FIG. 2 provides a schematic view of certain components of packaged terminal air conditioner unit 100, including sealed system 120. Sealed system 120 generally operates in a heat pump cycle. Sealed system 120 includes a compressor 122, an interior heat exchanger or coil 124 and an exterior heat exchanger or coil 126. As is generally understood, various conduits may be utilized to flow refrigerant between the various components of sealed system 120. Thus, e.g., interior coil 124 and exterior coil 126 may be between and in fluid communication with each other and compressor 122.

As may be seen in FIG. 2, sealed system 120 also includes a reversing valve 132. Reversing valve 132 selectively directs compressed refrigerant from compressor 122 to either interior coil 124 or exterior coil 126. For example, in a cooling mode, reversing valve 132 is arranged or configured to direct compressed refrigerant from compressor 122 to exterior coil 126. Conversely, in a heating mode, reversing valve 132 is arranged or configured to direct compressed refrigerant from compressor 122 to interior coil 124. Thus, reversing valve 132 permits sealed system 120 to adjust between the heating mode and the cooling mode, as will be understood by those skilled in the art.

During operation of sealed system 120 in the cooling mode, refrigerant flows from interior coil 124 flows through compressor 122. For example, refrigerant may exit interior coil 124 as a fluid in the form of a superheated vapor and/or high quality vapor mixture. Upon exiting interior coil 124, the refrigerant may enter compressor 122. Compressor 122 is operable to compress the refrigerant. Accordingly, the pressure and temperature of the refrigerant may be increased in compressor 122 such that the refrigerant becomes a more superheated vapor.

Exterior coil 126 is disposed downstream of compressor 122 in the cooling mode and acts as a condenser. Thus, exterior coil 126 is operable to reject heat into the exterior atmosphere at exterior side portion 114 of casing 110 when sealed system 120 is operating in the cooling mode. For example, the superheated vapor from compressor 122 may enter exterior coil 126 via a first distribution conduit 134 that extends between and fluidly connects reversing valve 132 and exterior coil 126. Within exterior coil 126, the refrigerant from compressor 122 transfers energy to the exterior atmosphere and condenses into a saturated liquid and/or liquid vapor mixture. An exterior air handler or fan 150 is positioned adjacent exterior coil 126 may facilitate or urge a flow of air from the exterior atmosphere across exterior coil 126 in order to facilitate heat transfer.

Sealed system 120 also includes a supply conduit 128 disposed between interior coil 124 and exterior coil 126, e.g., such that supply conduit 128 extends between and fluidly couples interior coil 124 and exterior coil 126. Refrigerant, which may be in the form of high liquid quality/saturated liquid vapor mixture, may exit exterior coil 126 and travel through supply conduit 128 before flowing through interior coil 124. The refrigerant may then be flowed through interior coil 124.

Supply conduit 128 may generally expand the refrigerant, lowering the pressure and temperature thereof. Thus, supply conduit 128 may function as a throttling device for sealed system 120. Supply conduit 128 may include various components for throttling refrigerant flow through supply conduit 128. For example, in the exemplary embodiment shown in FIG. 2, supply conduit 128 includes a pair of expansion valves 130 and a check valve 131 for throttling refrigerant flow through supply conduit 128. In alternative exemplary embodiments, sealed system 120 may include any other suitable device or mechanism for throttling the flow of refrigerant through supply conduit 128. For example, sealed system 120 may include a capillary tube and check valve, a J-T valve, an electronic expansion valve, etc. coupled to supply conduit 128 in order to throttle the flow of refrigerant through supply conduit 128, as will be understood by those skilled in the art.

Interior coil 124 is disposed downstream of supply conduit 128 in the cooling mode and acts as an evaporator. Thus, interior coil 124 is operable to heat refrigerant within interior coil 124 with energy from the interior atmosphere at interior side portion 112 of casing 110 when sealed system 120 is operating in the cooling mode. For example, the liquid refrigerant from supply conduit 128 may enter interior coil 124 via a second distribution conduit 136 that extends between and fluidly connects interior coil 124 and reversing valve 132. Within interior coil 124, the refrigerant from supply conduit 128 receives energy from the interior atmosphere and vaporizes into superheated vapor and/or high quality vapor mixture. An interior air handler or fan 148 is positioned adjacent interior coil 124 may facilitate or urge a flow of air from the interior atmosphere across interior coil 124 in order to facilitate heat transfer.

During operation of sealed system 120 in the heating mode, reversing valve 132 reverses the direction of refrigerant flow through sealed system 120. Thus, in the heating mode, interior coil 124 is disposed downstream of compressor 122 and acts as a condenser, e.g., such that interior coil 124 is operable to reject heat into the interior atmosphere at interior side portion 112 of casing 110. In addition, exterior coil 126 is disposed downstream of supply conduit 128 in the heating mode and acts as an evaporator, e.g., such that exterior coil 126 is operable to heat refrigerant within exterior coil 126 with energy from the exterior atmosphere at exterior side portion 114 of casing 110.

As discussed above, when the refrigerant enters supply conduit 128, refrigerant is mostly liquid and is typically subcooled below the saturation temperature. As the refrigerant flows through supply conduit 128, the refrigerant pressure decreases and refrigerant vapor bubbles form. As may be seen in FIG. 2, sealed system 120 includes a phase separator 160. Phase separator 160 is configured for separating liquid refrigerant within phase separator 160 from vapor refrigerant within phase separator 160. By separating liquid refrigerant from vapor refrigerant, phase separator 160 may improve a performance and/or efficiency of packaged terminal air conditioner unit 100, as discussed in greater detail below.

As may be seen in FIG. 2, phase separator 160 is coupled to supply conduit 128 at or adjacent interior coil 124. In particular, phase separator 160 may be positioned at or adjacent interior coil 124 within casing 110. Phase separator 160 receives refrigerant from supply conduit 128 and separates liquid refrigerant from supply conduit 128 from vapor refrigerant from supply conduit 128. The liquid phase refrigerant within phase separator 160 is directed from phase separator 160 to interior coil 124 via supply conduit 128. Conversely, the vapor phase refrigerant is directed around interior coil 124 such that the vapor phase refrigerant bypasses interior coil 124, as discussed in greater detail below.

Sealed system 120 includes a bypass conduit 162 for directing vapor phase refrigerant from phase separator 160 around interior coil 124. As may be seen in FIG. 2, bypass conduit 162 extends from phase separator 160 around interior coil 124, e.g., to second distribution conduit 136. Thus, vapor phase refrigerant within phase separator 160 may flow through bypass conduit 162 around interior coil 124 to second distribution conduit 136, e.g., when sealed system 120 is operating in the cooling mode. A bypass check valve 164 is coupled to bypass conduit 162. Bypass check valve 164 is configured for limiting or preventing refrigerant from flowing from second distribution conduit 136 to phase separator 160 around interior coil 124, e.g., when sealed system 120 in the heating mode.

To facilitate reintroduction of the vapor phase refrigerant from phase separator 160 into second distribution conduit 136, sealed system 120 may include an injector or ejector 166, e.g., configured for combining streams of refrigerant via the Venturi effect. Ejector 166 is positioned at a junction between bypass conduit 162 and second distribution conduit 136. Ejector 166 receives the vapor phase refrigerant from bypass conduit 162 and directs or urges the vapor phase refrigerant into second distribution conduit 136 and refrigerant flowing through second distribution conduit 136.

Ejector 166 may generate a resistance to refrigerant flow upstream from ejector 166 within bypass conduit 162. The resistance of ejector 166 may allow for or provide a balance in the pressure drops across bypass conduit 162 and across interior coil 124, e.g., such that the pressure drops across such components are equal or about (e.g., within ten percent of each other) equal. To provide such balance in pressure drops, bypass conduit 162 may have a smaller diameter than tubing within interior coil 124 and have a suitable length, as will be understood by those skilled in the art.

It should be understood that phase separator 160 may be any suitable type of phase separator. For example, phase separator 160 may be constructed in the same or similar manner to the phase separator described in U.S. patent application Ser. No. 14/088,558 of Brent Alden Junge and/or the phase separator described in U.S. patent application Ser. No. 14/258,397 of Brent Alden Junge et al., both of which are incorporated by reference herein for all purposes. Within a casing of phase separator 160, liquid phase refrigerant may collect or pool at a bottom portion of phase separator 160 and vapor phase refrigerant may collect or pool at a top portion of phase separator 160, e.g., due to density differences between the liquid and vapor phase refrigerants.

By directing vapor phase refrigerant around interior coil 124, a performance and/or efficiency of packaged terminal air conditioner unit 100 may be improved or increased. For example, at an entrance of the interior coil, refrigerant may be approximately twenty to thirty percent vapor by mass in previous packaged terminal air conditioner units. By volume however, the refrigerant is mostly vapor at the entrance of the interior coil because the vapor specific volume is many times larger than that of the liquid refrigerant. By providing phase separator 160 and separating liquid refrigerant from vapor refrigerant as described above, the velocity of refrigerant entering interior coil 124 may be greatly decreased. Such reduction in refrigerant velocity at the inlet of interior coil 124 may reduce a pressure drop across interior coil 124 without a significant reduction in cooling, e.g., because the quantity of liquid refrigerant is unchanged. In particular, phase separator 160 may reduce the pressure drop across interior coil 124 by more than fifty percent while only causing a small reduction in heat transfer. In such a manner, the efficiency of packaged terminal air conditioner unit 100 may be increased by five percent by providing phase separator 160 within sealed system 120 of packaged terminal air conditioner unit 100.

FIG. 3 provides a schematic view of certain components of packaged terminal air conditioner unit 100 with certain components of sealed system 120 rearranged relative to exemplary embodiment shown in FIG. 2. As may be seen in FIG. 3, in certain exemplary embodiments, bypass conduit 162 extends between and fluidly connects phase separator 160 and first distribution conduit 134. Ejector 166 is positioned at a junction between bypass conduit 162 and first distribution conduit 134. Thus, ejector 166 is configured for directing the vapor refrigerant in bypass conduit 162 into first distribution conduit 134 in the exemplary embodiment shown in FIG. 3. An ejector check valve 168 may also be plumed in parallel to ejector 166 on first distribution conduit 134 in order to bypass ejector 166 in the cooling mode.

It should be under that the exemplary embodiments of sealed system 120 provided in FIGS. 2 and 3 are provided by way of example only and that the components of sealed system 120 may have any other suitable arrangement in alternative exemplary embodiments. For example, phase separator 160 may be coupled to supply conduit 128 at or adjacent exterior coil 126. Thus, phase separator 160 may direct liquid refrigerant to exterior coil 126 via supply conduit 128 and vapor refrigerant may be directed around exterior coil 126 via bypass conduit 162, e.g., when sealed system 120 is operating in the heating mode, in certain exemplary embodiments. In such exemplary embodiments, sealed system 120 may have the same arrangement shown in FIG. 2, with the position of interior coil 124 and exterior coil 126 switched with each other.

This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims. 

What is claimed is:
 1. A packaged terminal air conditioner unit, comprising: a casing; a compressor positioned within the casing, the compressor operable to increase a pressure of a refrigerant; an interior coil positioned within the casing; an exterior coil positioned within the casing opposite the interior coil; a reversing valve positioned within the casing, the reversing valve in fluid communication with the compressor in order to receive compressed refrigerant from the compressor, the reversing valve configured for selectively directing the compressed refrigerant from the compressor to either the interior coil or the exterior coil; a supply conduit positioned within the casing, the supply conduit fluidly connecting the interior coil and the exterior coil in order to direct refrigerant between the interior coil and the exterior coil; and a phase separator positioned within the casing, the phase separator coupled to the supply conduit adjacent the interior coil, the phase separator configured for separating liquid refrigerant within the supply conduit from vapor refrigerant within the supply conduit, the supply conduit directing the liquid refrigerant from the phase separator to the interior coil.
 2. The packaged terminal air conditioner unit of claim 1, further comprising a bypass conduit and a check valve positioned within the casing, the bypass conduit extending from the phase separator around the interior coil, the bypass conduit configured for directing the vapor refrigerant out of the phase separator around the interior coil, the check valve coupled to the bypass conduit.
 3. The packaged terminal air conditioner unit of claim 2, further comprising an ejector, a first distribution conduit and a second distribution conduit, the first distribution conduit extending between the reversing valve and the exterior coil in order to fluidly connect the reversing valve and the exterior coil, the second distribution conduit extending between the reversing valve and the interior coil in order to fluidly connect the reversing valve and the interior coil, the bypass valve extending between the phase separator and the second distribution conduit, the ejector positioned at a junction between the bypass conduit and the second distribution conduit, the ejector configured for directing the vapor refrigerant in the bypass conduit into the second distribution conduit.
 4. The packaged terminal air conditioner unit of claim 3, wherein the reversing valve is selectively adjustable between a first configuration and a second configuration, the reversing valve directing the compressed refrigerant from the compressor to the exterior coil via the first distribution conduit when the reversing valve is in the first configuration, the reversing valve directing the compressed refrigerant from the compressor to the interior coil via the second distribution conduit when the reversing valve is in the second configuration.
 5. The packaged terminal air conditioner unit of claim 2, further comprising an ejector, a first distribution conduit and a second distribution conduit, the first distribution conduit extending between the reversing valve and the exterior coil in order to fluidly connect the reversing valve and the exterior coil, the second distribution conduit extending between the reversing valve and the interior coil in order to fluidly connect the reversing valve and the interior coil, the bypass valve extending between the phase separator and the first distribution conduit, the ejector positioned at a junction between the bypass conduit and the first distribution conduit, the ejector configured for directing the vapor refrigerant in the bypass conduit into the first distribution conduit.
 6. The packaged terminal air conditioner unit of claim 5, wherein the reversing valve is selectively adjustable between a first configuration and a second configuration, the reversing valve directing the compressed refrigerant from the compressor to the exterior coil via the first distribution conduit when the reversing valve is in the first configuration, the reversing valve directing the compressed refrigerant from the compressor to the interior coil via the second distribution conduit when the reversing valve is in the second configuration.
 7. The packaged terminal air conditioner unit of claim 1, wherein the supply conduit comprises a capillary tube and a check valve coupled to the capillary tube.
 8. The packaged terminal air conditioner unit of claim 1, further comprising a check valve and a pair of expansion valves positioned within the casing, the check valve and the expansion valves of the pair of expansion valves coupled the supply conduit, the check valve and a first one of the pair of expansion valves coupled to the supply conduit proximate the exterior coil, the check valve and the first one of the pair of expansion valves plumbed in parallel on the supply conduit, a second one of the pair of expansion valves coupled to the supply conduit proximate the interior coil.
 9. The packaged terminal air conditioner unit of claim 1, further comprising an electronic expansion valve coupled to the supply conduit.
 10. A packaged terminal air conditioner unit, comprising: a casing extending between an exterior side portion and an interior side portion; a compressor positioned within the casing, the compressor operable to compress a refrigerant; an interior coil positioned within the casing at the interior side portion of the casing; an exterior coil positioned within the casing at the exterior side portion of the casing; a reversing valve in fluid communication with the compressor in order to receive compressed refrigerant from the compressor, the reversing valve configured for selectively directing the compressed refrigerant from the compressor to either the interior coil or the exterior coil; a supply conduit extending between the interior coil and the exterior coil; and a phase separator coupled to the supply conduit, the phase separator configured for separating liquid refrigerant within the supply conduit from vapor refrigerant within the supply conduit, the supply conduit configured for directing the liquid refrigerant from the phase separator to the interior coil.
 11. The packaged terminal air conditioner unit of claim 10, further comprising a bypass conduit and a check valve positioned within the casing, the bypass conduit extending from the phase separator around the interior coil, the bypass conduit configured for directing the vapor refrigerant out of the phase separator around the interior coil, the check valve coupled to the bypass conduit.
 12. The packaged terminal air conditioner unit of claim 11, further comprising an ejector, a first distribution conduit and a second distribution conduit, the first distribution conduit extending between the reversing valve and the exterior coil in order to fluidly connect the reversing valve and the exterior coil, the second distribution conduit extending between the reversing valve and the interior coil in order to fluidly connect the reversing valve and the interior coil, the bypass valve extending between the phase separator and the second distribution conduit, the ejector positioned at a junction between the bypass conduit and the second distribution conduit, the ejector configured for directing the vapor refrigerant in the bypass conduit into the second distribution conduit.
 13. The packaged terminal air conditioner unit of claim 12, wherein the reversing valve is selectively adjustable between a first configuration and a second configuration, the reversing valve directing the compressed refrigerant from the compressor to the exterior coil via the first distribution conduit when the reversing valve is in the first configuration, the reversing valve directing the compressed refrigerant from the compressor to the interior coil via the second distribution conduit when the reversing valve is in the second configuration.
 14. The packaged terminal air conditioner unit of claim 11, further comprising an ejector, a first distribution conduit and a second distribution conduit, the first distribution conduit extending between the reversing valve and the exterior coil in order to fluidly connect the reversing valve and the exterior coil, the second distribution conduit extending between the reversing valve and the interior coil in order to fluidly connect the reversing valve and the interior coil, the bypass valve extending between the phase separator and the first distribution conduit, the ejector positioned at a junction between the bypass conduit and the first distribution conduit, the ejector configured for directing the vapor refrigerant in the bypass conduit into the first distribution conduit.
 15. The packaged terminal air conditioner unit of claim 14, wherein the reversing valve is selectively adjustable between a first configuration and a second configuration, the reversing valve directing the compressed refrigerant from the compressor to the exterior coil via the first distribution conduit when the reversing valve is in the first configuration, the reversing valve directing the compressed refrigerant from the compressor to the interior coil via the second distribution conduit when the reversing valve is in the second configuration.
 16. The packaged terminal air conditioner unit of claim 10, wherein the supply conduit comprises a capillary tube and a check valve coupled to the capillary tube.
 17. The packaged terminal air conditioner unit of claim 10, further comprising a check valve and a pair of expansion valves positioned within the casing, the check valve and the expansion valves of the pair of expansion valves coupled the supply conduit, the check valve and a first one of the pair of expansion valves coupled to the supply conduit proximate the exterior coil, the check valve and the first one of the pair of expansion valves plumbed in parallel on the supply conduit, a second one of the pair of expansion valves coupled to the supply conduit proximate the interior coil
 18. The packaged terminal air conditioner unit of claim 10, further comprising an electronic expansion valve coupled to the supply conduit.
 19. A packaged terminal air conditioner unit, comprising: a casing; a compressor positioned within the casing, the compressor operable to increase a pressure of a refrigerant; an interior coil positioned within the casing; an exterior coil positioned within the casing opposite the interior coil; a reversing valve positioned within the casing, the reversing valve in fluid communication with the compressor in order to receive compressed refrigerant from the compressor, the reversing valve configured for selectively directing the compressed refrigerant from the compressor to either the interior coil or the exterior coil; a supply conduit positioned within the casing, the supply conduit fluidly connecting the interior coil and the exterior coil in order to direct refrigerant between the interior coil and the exterior coil; and a phase separator positioned within the casing, the phase separator coupled to the supply conduit adjacent the exterior coil, the phase separator configured for separating liquid refrigerant within the supply conduit from vapor refrigerant within the supply conduit, the supply conduit directing the liquid refrigerant from the phase separator to the exterior coil. 